mcs/class/corlib/System.Security.Permissions/ZoneIdentityPermission.cs

   1 //
   2 // System.Security.Permissions.ZoneIdentityPermission
   3 //
   4 // Authors:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //      Sebastien Pouliot  <sebastien@ximian.com>
   7 //
   8 // (C) 2002 Ximian, Inc (http://www.ximian.com)
   9 // Copyright (C) 2004 Novell, Inc (http://www.novell.com)
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 using System.Globalization;
  32
  33 namespace System.Security.Permissions {
  34
  35         [Serializable]
  36         public sealed class ZoneIdentityPermission : CodeAccessPermission, IBuiltInPermission {
  37
  38                 private const int version = 1;
  39
  40                 private SecurityZone zone;
  41
  42                 public ZoneIdentityPermission (PermissionState state)
  43                 {
  44                         // false == do not allow Unrestricted for Identity Permissions
  45                         CheckPermissionState (state, false);
  46                         // default values
  47                         zone = SecurityZone.NoZone;
  48                 }
  49
  50                 public ZoneIdentityPermission (SecurityZone zone)
  51                 {
  52                         // also needs the validations
  53                         SecurityZone = zone;
  54                 }
  55
  56                 public override IPermission Copy ()
  57                 {
  58                         return new ZoneIdentityPermission (zone);
  59                 }
  60
  61                 public override bool IsSubsetOf (IPermission target)
  62                 {
  63                         ZoneIdentityPermission zip = Cast (target);
  64                         if (zip == null)
  65                                 return (zone == SecurityZone.NoZone);
  66
  67                         return ((zone == SecurityZone.NoZone) || (zone == zip.zone));
  68                 }
  69
  70                 public override IPermission Union (IPermission target)
  71                 {
  72                         ZoneIdentityPermission zip = Cast (target);
  73                         if (zip == null)
  74                                 return (zone == SecurityZone.NoZone) ? null : Copy ();
  75
  76                         if (zone == zip.zone || zip.zone == SecurityZone.NoZone)
  77                                 return Copy ();
  78
  79                         if (zone == SecurityZone.NoZone)
  80                                 return zip.Copy ();
  81 #if NET_2_0
  82                         throw new ArgumentException (Locale.GetText (
  83                                 "Union impossible"));
  84 #else
  85                         return null;
  86 #endif
  87                 }
  88
  89                 public override IPermission Intersect (IPermission target)
  90                 {
  91                         ZoneIdentityPermission zip = Cast (target);
  92                         if (zip == null || zone == SecurityZone.NoZone)
  93                                 return null;
  94
  95                         if (zone == zip.zone)
  96                                 return Copy ();
  97
  98                         return null;
  99                 }
 100
 101                 public override void FromXml (SecurityElement esd)
 102                 {
 103                         // General validation in CodeAccessPermission
 104                         CheckSecurityElement (esd, "esd", version, version);
 105                         // Note: we do not (yet) care about the return value
 106                         // as we only accept version 1 (min/max values)
 107
 108                         string zoneName = esd.Attribute ("Zone");
 109                         if (zoneName == null)
 110                                 zone = SecurityZone.NoZone;
 111                         else
 112                                 zone = (SecurityZone) Enum.Parse (typeof (SecurityZone), zoneName);
 113                 }
 114
 115                 public override SecurityElement ToXml ()
 116                 {
 117                         SecurityElement se = Element (version);
 118                         if (zone != SecurityZone.NoZone)
 119                                 se.AddAttribute ("Zone", zone.ToString ());
 120                         return se;
 121                 }
 122
 123                 public SecurityZone SecurityZone {
 124                         get { return zone; }
 125                         set {
 126                                 if (!Enum.IsDefined (typeof (SecurityZone), value)) {
 127                                         string msg = String.Format (Locale.GetText ("Invalid enum {0}"), value);
 128                                         throw new ArgumentException (msg, "SecurityZone");
 129                                 }
 130                                 zone = value;
 131                         }
 132                 }
 133
 134                 // IBuiltInPermission
 135                 int IBuiltInPermission.GetTokenIndex ()
 136                 {
 137                         return (int) BuiltInToken.ZoneIdentity;
 138                 }
 139
 140                 // helpers
 141
 142                 private ZoneIdentityPermission Cast (IPermission target)
 143                 {
 144                         if (target == null)
 145                                 return null;
 146
 147                         ZoneIdentityPermission zip = (target as ZoneIdentityPermission);
 148                         if (zip == null) {
 149                                 ThrowInvalidPermission (target, typeof (ZoneIdentityPermission));
 150                         }
 151
 152                         return zip;
 153                 }
 154         }
 155 }
 156